Screw-driver attachment



Oct. 21 1924.

G. G. NAUGLE ET AL SCREW DRIVER ATTACHMENT Filed Avril 21, 1923 anoewbom k N .2 L 2226 kW w Patented Oct. 21, 1924.

UNITED STATES PATENT OFFICE.

GIRARDUS Gr. NAUG-LE AND CARLTON L. HOFF, OF YORK, PENNSYLVANIA; SAID NAUGLE ASSIGNOR TO SAID HOFF.

SCREW-DRIVER ATTACHMENT.

Appllication filed April 21, 1923.

To all whom it may concern:

Be it known that we, Grnnnnus G. NAUGLE and CARLTON L. Horn, citizens of the United States, residing at York, in the county of York and State of Pennsylvania, have invented certain new and useful Improvements in Screw-Driver Attachments; and we do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

This invention relates to screw drivers in general and has for its object the provision of an attachment for holding a screw while it is being inserted and for permitting the screw driver to advance beyond the surface into which the screw is driven as in countersinking.

A further object of the invention is the provision of a screw driver having a helical groove cut in its stem and a spring fingered sleeve engageable with said groove at one end and resiliently receiving the head of the screw at the other end.

It is old at the present time to attach appliances of various kinds to screw drivers for the purpose of holding a screw while the latter is being driven but most of these devices prevent the entry of the edge of the screw driver blade below the plane of the upper surface of the wood or metal work, rendering the device useless when screws are to be countersunk. It is believed to be new at the present time to provide a screw holding sleeve controlled by a screw thread on thestem or shank of a screw driver.

In the drawings ,accompa-nying'this application we have illustrated a preferred form of sleeve and shown same in combination with a screw driver of well known and common type except for the provision of the helical groove.

Figure 1 is a side view of a screw driver embodying the present invention.

Fig. 1 is a detail, longitudinal section of a portion of the screw driver at the inner extremity of the screw holding member.

Figure 2 is a view on a somewhat larger scale of the sleeve detachedfrom the screw driver.

Figure 3 is a cross section through a modification.

Figure 4 is an end view of the driver and sleeve.

Serial No. 633,708.

The screw driver shown in Figure 1 is of ordinary type having a long shank or stem 10 extending at one end within a ferrule 11 of steel on a usual wooden handle 12. As is customary in the art the stem 10 is reduced at the end opposite the tang, forming a blade 15 having a thin edge 16 adapted to enter in the slot of a screw.

The only novel feature of the screw driver per so as shown is the helical groove 17 which is cut in the stem of the driver a short distance back of the blade 15. This helical groove 1? should be of such length as to provide for varied lengths of the blade or driver end as may be occasioned by wear or breakage and is in addition of such length as to provide for the longest screw that may be used with the driver. Although not essential, we find it very convenient to form the helical groove with its rear edge, that is, the edge nearest the handle either slightly undercut or radial, and with its forward edge sloping at an angle of from 30 to degrees with the axis of the shank.

The sleeve 20 is preferably formed of a tube of high carbon steel having a slot 21 extending a considerable distance back from the forward edge thus providing resilient screw holding spring fingers 23 On its opposite end the tube is again slotted as at 24 providing two somewhat shorter resilient members 25 and 26 preferably of unequal length, at least one of which engages the helical groove having an inwardly directed angularly disposed lip 27 resiliently engaging the groove. I

It is preferable that each of the two members 25 and 26 have a groove engaging lip 27 and that each lip engage the groove thus requiring that the members 25 and 26 shall differ in length by a distance equal to one half of the pitch of the groove. In the modified form shown in 3, however, we have shown the member 26 as being lipless as we find that the single member 25 affords sufficient engagement with the groove to accomplish the purpose desired under usual circumstances.

As best seen in Fig. 3, the structure of which is identical with that shown in Fig. 2 save for the provision of a straight nonlipped edge 30 in place of the lipped edge 26 of the preferred form, the bore of the tube is enlarged from the forward end of the sleeve back to the solid portion 33 of the tube in order to provide a materially greater resiliency for the fingers 23 than possessed by the members 25 and 26, the resiliency of members 25 and 26 being less than that of fingers 23 because of the reduced bore of the inner portion 32 of the tube. We find it convenient to have the initial bore of the tube but slightly greater than the diameter of the shank or stem 10 which gives a considerable clearance between the stem and the fingers 23 and which permits of a very substantial engagement between the inwardly-turned lips 27 and the stem.

The operation of the device is quite simple. The screw to be inserted is placed between the spring fingers 23 with the slot of the screw in engagement with the edge 16 0f the driver and the screw is inserted in the work in the usual manner until. such time as the outer edge of the spring fingers 23 come into contact with the surface. At such time the friction between the surface and the spring fingers prevents the sleeve from turning and the screw driver stem advances on the sleeve until the screw is seated. The construction is such that if the screw is to be countersunk the screw driver blade may readily pass the forward edge of the sleeve.

A very important advantage of the constru-ction shown lies in the ease of withdrawing a countersunk screw by moving the sleeve back on the helical groove so that thepoint'of the screw driver will project beyondthe sleeve the same as in inserting the screw and when the screw head is projected beyond the surface the sleeve can be brought forward on the helical groove by turning it by hand and by holding the screw driver firmly against the screw the sleeve will very readily engage the head of the screw and the screw can then be entirely withdrawn and held firmly by the sleeve of the screw driver so that upon withdrawal the screw will not fall.

lVhat we claim is:

l. 'A screw driver having a groove in its stem, resilient means for detachably engagin a screw, comprising a member having an open end through which the stem may extend, and means engaging said groove to control the movement of said resilient means and retract said resilient means on the stem as the screw is driven home.

2. A screw driver having a helical groove on its stem, resilient means for detachably engaging a screwhead comprising a member having an open end through which the stem may extend, and means engaging said groove to control the movement of said reilient means and retract said resilient means on the stem as the screw is driven home.

3. A screwdriver having a groove in its stem, a tubular sleeve on said stem. resilient ieans carried by said sleeve for holding the screws, said resilient means being open whereby the stem may be projected beyond the end thereof, and means on the sleeve engaging said groove for retracting the sleeve and screw holding means on the stem as the screw is driven home.

at. A screw driver having a helical groove in its stem, a cylindrical sleeve slidable on said stem and slotted at each end to provide a plurality of pairs of resilient members, one pair of said members gripping said groove to move the sleeve longitudinally of the stem upon rotation of the screw driver and the other pair of said members serving as resilient screw holding means.

A. screw driver having a helical groove on its stem, a tubular sleeve slotted at car-h end to provide a plurality of pairs of resilient members, the members 0 one pair being of unequal length and gripping said groove at diametrically opposite sides and the other pair of resilient members serving as screw holding fingers.

6. A screw driver having a. helical groove in its stem adjacent its blade end, a tubular sleeve slidable on said stem and slotted to provide a plurality of resilient members, an. inturned lip on one end of said members engageable with said groove to control the movement of said sleeve, and a slotted ex tension on said sleeve having a greater internal bore than said sleeve and mailing a resilient screw holding means.

7. A screw driver having a helical groove in. its stem near the blade end, a screw holding sleeve slidable on said stein, a plurality of members extending from said sleeve each having an inturned angularly disposed lip engageable with said groove.

8. A screw driver having a helical groove in its stem near the blade end, said groove having one sloping side and one substantially radial side and a screw engaging member secured at one end in said helical groove and open at its opposite end to permit the stem to pass beyond said member.

GIRARDUS G. NAUGLE. CARLTON L. HOFF. lVitness:

GEORGE S. DELLINGER. 

